Controllable Synthesis of Cadmium-Free Blue-Emitting Cu-Ga-Zn-S-Based Nanocrystals for Solution-Processed Quantum-Dot Light-Emitting Diodes.

The utility of semiconductor nanocrystals (NCs) in light-emitting diodes (LED) has shown great potential in the field of display, whereas the challenge remains in developing efficient and stable cadmium-free blue-emitting LED devices due to the poor photophysical properties of blue-emitting NCs. Herein, we develop a controllable synthesis of Cu-Ga-Zn-S (CGZS) semiconductor NCs that show blue light emission with a relative photoluminescence quantum yield exceeding 90%. Furthermore, we have successfully fabricated a solution-processed quantum-dot LED (QLED) using CGZS NCs, achieving a notable maximum external quantum efficiency (EQE) of 1.00% at a luminance of 100 cd/m. Our work lays a foundational framework for advancing cadmium-free blue-emitting QLEDs and facilitates the development of quantum dot electroluminescent panchromatic displays.